1. Field of the Invention
The present invention relates to a carrier identification system for transferring semiconductor devices, and so forth, in an auto handler, a carrier identification method, and storage media.
2. Related Art
In an IC testing system for measuring electric properties of semiconductor devices such as an IC (integrated circuit), and so forth, use is made of an auto handler for transferring devices as objects for measurement. Semiconductor devices as objects for testing are mounted in a carrier, and selected by the auto handler.
In such a case, a plurality of carriers are simultaneously circulated inside the auto handler in order to improve efficiency, thereby selecting ICs.
Further, since the form of the carriers varies depending on a type of the semiconductor devices as the objects for testing, a controller of the auto handler needs to identify types of the semiconductor devices to be tested.
It is further required that, for example, nine units of the carriers are circulated inside the auto handler, and the respective carriers are assigned a serial number so as to be able to monitor all the time where the respective carriers are located inside the auto handler.
Accordingly, with a conventional auto handler, the respective carriers are assigned a bar code for carrier identification in order to identify a type of a semiconductor device mounted in the respective carriers, and the serial number of the respective carriers. A bar code reader reads the bar code assigned to the respective carriers, and identify the type of the semiconductor device mounted in the respective carriers, and the serial number of the respective carriers, on the basis of the bar code as read.
The above-described method is disclosed by the applicant of the present invention in, for example, Japanese Patent Application No. H 10-377095.
Further, there is available another method of identifying a type of semiconductor devices whereby a plurality of holes for identification are formed on a carrier. With this method, a plurality of sensors installed so as to correspond to the respective holes for identification read the holes for identification, provided in the carrier, and identify the type of semiconductor devices mounted in the carrier depending on a state of the holes, as read.
However, with the former method as described, the carrier needs to be stopped every time there is a need of reading data for carrier identification, and it has also been required that a location for stopping the carrier be in full agreement with that of a sensor for reading.
Meanwhile, with the latter method as described, whereby the holes for identification are formed in the carrier, it has been required that as many sensors for reading out as the holes for identification be installed.
Thus, problems to be solved by the invention are to eliminate a need of stopping carriers for transferring devices in order to read the data for carrier identification, and to be able to do with less numbers of the sensors for reading the data for carrier identification.
To solve the problems as described above, a carrier identification system according the first aspect of the invention, comprises a carrier (for example, a carrier 1 in FIG. 1) for mounting and transferring a plurality of devices to be tested (hereinafter referred to as DUTs), having identification information thereof, reading means (for example, a timing hole detection sensor 5 and a data hole detection sensor 6, in FIG. 1) for reading the identification information of the carrier, and identification means (for example, a device type identifying circuit 9 in FIG. 1) for identifying the carrier on the basis of the identification information as read by the reading means, wherein the carrier is provided with a plurality of timing holes (for example, timing holes 3 in FIG. 1) arranged in parallel with a direction of carrier transfer, and a plurality of data holes (for example, data holes 4 in FIG. 1) arranged in parallel with the direction of the carrier transfer, corresponding to arrangement locations of the plurality of the timing holes, and the reading means is provided with timing detection means (for example, timing hole detection sensor 5 in FIG. 1) disposed so as to correspond to the arrangement locations of the plurality of the timing holes, for detecting the plurality of the timing holes in conjunction with the carrier transfer, and data detection means (for example, data hole detection sensor 6 in FIG. 1) disposed so as to correspond to arrangement locations of the plurality of the data holes, for detecting the plurality of the data holes in conjunction with detection of the plurality of the timing holes by the timing detection means.
Further, a carrier identification method according to the third aspect of the invention comprises a transfer step of transferring a plurality of DUTs by use of a carrier with the plurality of the devices mounted therein, a reading step for reading identification information provided in the carrier, and an identification step of identifying the carrier on the basis of the identification information as read, said reading step including a timing detection step of detecting a plurality of timing holes arranged on the carrier, in parallel with a direction of carrier transfer, in conjunction with the carrier transfer, and a data detection step of detecting a plurality of data holes arranged on the carrier, in parallel with the direction of the carrier transfer, in conjunction with the timing detection step.
Therefore, according to the first and third aspects of the invention, the plurality of the timing holes and the data holes, disposed as the identification display in the carrier with the devices mounted therein, can be read one after another by the timing hole detection sensor and the data hole detection sensor, respectively, while the carrier is being transferred. As a result, it is possible to eliminate a need of stopping the carrier every time the identification display is read.
Further, as the sensors for reading the identification holes or markers on the carrier, only two kinds of sensors, that is, the timing hole detection sensor and the data hole detection sensor, are sufficient, and the number of the timing holes and the data holes can be increased or decreased with ease so as to correspond to the number of types of the carriers to be identified.
The invention according to the second aspect of the invention is a carrier identification system in the first aspect of the invention, wherein the timing detection means detect the plurality of the timing holes by transmission or shutoff of light (passage through the holes), the data detection means detect whether or not there exist the plurality of the data holes by transmission or shutoff of light, and the identification means generate a given code or data row according to whether or not there exist the plurality of the data holes as detected, thereby identifying the carrier on the basis of the data row as generated. The code row is defined as the output of the row of data holes and is a specific pattern depending on the type of carrier.
The invention according to the fourth aspect of the invention is a carrier identification method in the third aspect of the invention, wherein the timing detection step detects the plurality of the timing holes by transmission or shutoff of light, the data detection step detects whether or not there exist the plurality of the data holes by transmission or shutoff of light, and the identification step generates a given code row, corresponding to each data hole row, according to whether or not there exist the plurality of the data holes as detected, thereby identifying the carrier on the basis of the data hole row as generated or sensed.
Therefore, according to the second, fourth and sixth aspects of the invention, a state of the respective timing holes as well as the respective data holes as identification information can be detected by two kinds of states, that is, transmission and shutoff of light. By outputting and extracting such states as detected as digital signals, it is possible to set data rows wherein xe2x80x9c1xe2x80x9d and xe2x80x9c0xe2x80x9d are arranged. The DUTs can be identified by use of the data rows as the carrier identification information as DUTs known to be placed in the specific carrier.